Why Bike Helmet Laws Don’t Work

Bike-share programs have proved hugely popular in hundreds of cities around the world—but not in Australia. While bikes in the London and New York systems see three to six trips a day each, their unloved peers in Melbourne are lucky to be used once. One study declared Brisbane’s system to be the least popular in the world. Their shortcomings are partly due to flaws in the networks, but there’s another factor at play: helmet laws.

If you use bike shares in London, New York, Paris, or Hangzhou, you can bring a helmet if you want, or just leap on and pedal away. Do that in Melbourne or Brisbane and you risk being fined by police because of compulsory helmet-use laws. Both systems have tried to get around this by leaving complimentary helmets on the bikes—Melbourne leaves 1,000 new ones a month—or selling cheap helmets nearby. But for many people, it’s simply too much trouble.

This is one of the many accidental effects of helmet compulsion. Even in a youthful, vibrant city like Melbourne, a bike-share program is a nonstarter. A small if significant opportunity for creating a human-friendly city is lost.

Proponents of helmet laws usually argue something like: “If a bike helmet law saves just one life, it will be worth it.” But the accidental effects of bike helmet laws can go much further than just undermining bike-share systems—they can also take a toll on public health.

In 1993, New South Wales, Australia, commissioned a study to see if a new helmet law for children was increasing helmet uptake. It did—but the researchers also found 30 percent fewer children were riding to school. In New Zealand, where helmet compulsion was introduced in 1994, the number of overall bike trips fell 51 percent between 1989–90 and 2003–6, according to one research paper. The reasons are mixed: Some people simply don’t want to bother with a helmet. For others, helmet laws reinforce the notion that cycling isn’t an everyday way to get about, but rather a specialist pursuit requiring special safety equipment. And if a law does mean fewer cyclists, it could also have a reverse “safety in numbers” effect: Fewer riders on the road could place those remaining at more individual risk.

Proponents of helmet laws present themselves as being led by evidence, so it seems right to approach them on those terms. The only part of the U.K. to have introduced such a law is Jersey, which, in 2014, imposed a £50 fine on parents whose children cycled without helmets. Wearing a helmet makes even more sense for children than it does for adults: They are more likely to fall off and, when they do, are more likely to hurt their heads, as young bodies are disproportionately weighted toward the skull. That said, there is currently no evidence that Jersey’s law will achieve anything at all.

When the Transport Research Laboratory evaluated Jersey’s plan, it found that 84 percent of children wore helmets in the year before the ban, and not a single under-14 had been seriously hurt on a bike. Even if the law suddenly meant every child wore a helmet, which is unlikely, that’s still a 16-percentage-point improvement for zero casualties. Research published in the British Medical Journal in 2006 drew a similar conclusion: The idea that bike helmet laws directly improve overall safety for cyclists doesn’t appear to be backed by any evidence from countries where they have actually been passed.